/**
 * Copyright 2018 The AMP HTML Authors. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS-IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { fetchAndInstall } from './install';
import { ExportedWorker } from './exported-worker';

export function upgradeElement(baseElement: Element, domURL: string): Promise<ExportedWorker | null> {
  const authorURL = baseElement.getAttribute('src');
  if (authorURL) {
    return fetchAndInstall(baseElement as HTMLElement, {
      authorURL,
      domURL,
    });
  }
  return Promise.resolve(null);
}
